The present invention relates to razors and, in particular, it concerns a razor cartridge employing narrow blades, and a method for assembling such cartridges.
Modern razor cartridges typically employ one of two techniques for retaining blades in position within the cartridge. The first employs a plurality of pins projecting from one of the cartridge elements which engage locating holes formed through each blade. An example of such a structure is U.S. Pat. No. 4,860,449 to Duncan.
The presence of locating holes within the blades required a certain minimum width of blade to ensure the structural integrity of the blades. Thus, blades of this type are typically at least about 5.5 mm wide. Since the total width of the cartridge is typically of the order of 10 mm, the use of two 5.5 mm blades requires that the blades are set in overlapping relation with a spacer element therebetween. This overlap greatly limits the area of drainage channels between the blades for flushing out hair and dirt, thereby leading to clogging of the cartridge.
In an attempt to reduce overlap between the blades, The Gillette Company.RTM. has developed a second blade retention technique which employs brazing of narrow blades onto a bent-over metal support element. An example of the resulting structure may be found in U.S. Pat. No. 5,056,222 to Miller et al.
The Gillette approach avoids the need for forming holes in the blades, thereby allowing a reduction in width of the blades to eliminate overlap and provide better drainage channels. This, however, is achieved at considerable cost. Specifically, the production techniques during which the blades are brazed onto the support elements are complex and expensive, leading to increased cost of the cartridge as a whole.
There is therefore a need for a razor cartridge which would employ narrow blades of no more than about 4 mm width without requiring either holes formed through the blades or brazing of the blades to support elements. It would also be highly advantageous to provide a method for assembling such a razor cartridge.